JP6060024B2 - Resist composition and method for producing resist pattern - Google Patents

Description

  The present invention relates to a resist composition, a method for producing a resist pattern using the resist composition, and the like.

Patent Document 1 discloses a resin composed of a structural unit represented by the formula (u-A) and a structural unit represented by the formula (u-B) as a resin, and a structure represented by the formula (u-C). A resin comprising a unit, a structural unit represented by the formula (u-D) and a structural unit represented by the formula (u-B), and containing a salt represented by the formula (x) as an acid generator A resist composition is described.

JP 2010-197413 A

  Conventional resist compositions sometimes do not always satisfy the focus margin (DOF) at the time of producing a resist pattern, and sometimes have defects.

［式（Ｉ）中、
Ｒ^１は、水素原子又はメチル基を表す。
Ａ^１は、−（ＣＨ_２）_ｍ１−、−（ＣＨ_２）_ｍ２−Ｏ−（ＣＨ_２）_ｍ３−又は−（ＣＨ_２）_ｍ４−ＣＯ−Ｏ−（ＣＨ_２）_ｍ５−を表す。
ｍ１〜ｍ５は、それぞれ独立に、１〜６の整数を表す。
Ｒ^２は、フッ素原子を有する炭素数１〜１０の炭化水素基を表す。］

［式（ＩＩ）中、
Ｑ^１及びＱ^２は、互いに独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^１は、２価の炭素数１〜１７の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。
環Ｗは、炭素数３〜３６の脂環式炭化水素環を表し、該脂環式炭化水素環に含まれるメチレン基は、酸素原子、硫黄原子、カルボニル基又はスルホニル基で置換されていてもよく、該脂環式炭化水素環に含まれる水素原子は、水酸基、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、炭素数３〜１２の脂環式炭化水素基又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。
Ｒ^ｆ１及びＲ^ｆ２は、互いに独立に、フッ素原子又は炭素数１〜６のフッ化アルキル基を表す。
ｓは、１〜１０の整数を表し、ｓが２以上の場合、複数のＲ^ｆ１及びＲ^ｆ２はそれぞれ同一又は相異なる。
Ｚ^＋は、有機カチオンを表す。］
［２］Ｒ^２が、炭素数１〜６のフッ化アルキル基である［１］記載のレジスト組成物。
［３］Ａ^１が、メチレン基である［１］又は［２］記載のレジスト組成物。
［４］環Ｗが、式（Ｉａ１−１）で表される環、式（Ｉａ１−２）で表される環又は式（Ｉａ１−３）で表される環である［１］〜［３］のいずれか記載のレジスト組成物。

［式（ＩＩａ１−１）、式（ＩＩａ１−２）及び式（ＩＩａ１−３）中、
環に含まれるメチレン基は、酸素原子、硫黄原子、カルボニル基又はスルホニル基で置き換わっていてもよく、環に含まれる水素原子は、水酸基、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、炭素数３〜１２の脂環式炭化水素基又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。］
［５］Ｌ^１が、＊−ＣＯ−Ｏ−（ＣＨ_２）_t−（ｔは０〜６の整数を表す。＊は、−Ｃ（Ｑ^１）（Ｑ^２）−との結合手を表す。）である［１］〜［４］のいずれか記載のレジスト組成物。
［６］さらに溶剤を含有する［１］〜［５］のいずれか記載のレジスト組成物。
［７］（１）上記［１］〜［６］のいずれか記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層を露光する工程、
（４）露光後の組成物層を加熱する工程及び
（５）加熱後の組成物層を現像する工程を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] (A1) a resin having a structural unit represented by formula (I),
(A2) A resist composition containing a resin having an acid labile group and (B) an acid generator represented by formula (II).

[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ _{is, - (CH 2) m1 -} , - (CH 2) m2 -O- (CH 2) m3 - or _{- (CH 2) m4 -CO-} O- (CH 2) m5 - represents a.
m1 to m5 each independently represents an integer of 1 to 6.
R ² represents a C 1-10 hydrocarbon group having a fluorine atom. ]

[In the formula (II),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon ring may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. Well, the hydrogen atom contained in the alicyclic hydrocarbon ring is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or carbon. The aromatic hydrocarbon group of several 6-10 may be substituted.
R ^f1 and R ^f2 each independently represent a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
s represents an integer of 1 to 10, and when s is 2 or more, the plurality of R ^f1 and R ^f2 are the same or different.
Z ⁺ represents an organic cation. ]
[2] The resist composition according to [1], wherein R ² is a fluorinated alkyl group having 1 to 6 carbon atoms.
[3] The resist composition according to [1] or [2], wherein A ¹ is a methylene group.
[4] Ring W is a ring represented by formula (Ia1-1), a ring represented by formula (Ia1-2) or a ring represented by formula (Ia1-3) [1] to [3 ] The resist composition in any one of these.

[In Formula (IIa1-1), Formula (IIa1-2) and Formula (IIa1-3),
The methylene group contained in the ring may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group, and the hydrogen atom contained in the ring is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms. May be substituted with an alkoxy group, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms. ]
[5] L ¹ represents * —CO—O— (CH ₂ ) _t — (t represents an integer of 0 to 6. * represents a bond to —C (Q ¹ ) (Q ² ) —. .) The resist composition according to any one of [1] to [4].
[6] The resist composition according to any one of [1] to [5], further containing a solvent.
[7] (1) A step of applying the resist composition according to any one of [1] to [6] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  According to the resist composition of the present invention, a resist pattern with an excellent focus margin (DOF) and few defects can be obtained.

In this specification, "(meth) acrylic monomer" means at least one monomer having the structure of _"CH 2 = _CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " To do. Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

<Resist composition>
The resist composition of the present invention comprises:
(A) Resin (hereinafter sometimes referred to as “resin (A)”) and (B) an acid generator represented by the formula (II).
Here, the resin (A) includes the following resins.
(A1) Resin having a structural unit represented by the formula (I) (hereinafter sometimes referred to as “resin (A1)”) and (A2) Resin having an acid labile group (hereinafter referred to as “resin (A2)”) Is).
The resist composition of the present invention preferably further contains a solvent (E) (hereinafter sometimes referred to as “solvent (E)”).
The resist composition of the present invention preferably further contains a basic compound (hereinafter sometimes referred to as “basic compound (C)”).

［式（Ｉ）中、
Ｒ^１は、水素原子又はメチル基を表す。
Ａ^１は、−（ＣＨ_２）_ｍ１−、−（ＣＨ_２）_ｍ２−Ｏ−（ＣＨ_２）_ｍ３−又は−（ＣＨ_２）_ｍ４−ＣＯ−Ｏ−（ＣＨ_２）_ｍ５−を表す。
ｍ１〜ｍ５は、それぞれ独立に、１〜６の整数を表す。
Ｒ^２は、フッ素原子を有する炭素数１〜１０の炭化水素基を表す。］ <Resin (A1)>
The resin (A1) has a structural unit represented by the following formula (I) (hereinafter sometimes referred to as “structural unit (I)”).

[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ _{is, - (CH 2) m1 -} , - (CH 2) m2 -O- (CH 2) m3 - or _{- (CH 2) m4 -CO-} O- (CH 2) m5 - represents a.
m1 to m5 each independently represents an integer of 1 to 6.
R ² represents a C 1-10 hydrocarbon group having a fluorine atom. ]

The hydrocarbon group for R ² includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and the aliphatic hydrocarbon group includes a chain type, a cyclic type, and a combination thereof. As the aliphatic hydrocarbon group, an alkyl group or an alicyclic hydrocarbon group is preferable.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. .
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a methyl group. Examples thereof include cycloalkyl groups such as cyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, and norbornyl. Group, methylnorbornyl group and isobornyl group.

Examples of the hydrocarbon group having a fluorine atom include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
Examples of the alkyl group having a fluorine atom include difluoromethyl group, trifluoromethyl group, 1,1,1-trifluoroethyl group, perfluoroethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2 , 2,2-trifluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, 1,1,1,2,2- Pentafluoropropyl group, perfluoropropyl group, 1,1,1,2,2,3,3-peptafluorobutyl group, perfluorobutyl group, 1,1,1,2,2,3,3,4,4 -Fluoroalkyl groups such as nonafluoropentyl group, perfluoropentyl group, perfluorohexyl group, perfluoroheptyl group and perfluorooctyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom include fluorinated cycloalkyl groups such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

In the formula (I), A ¹ is preferably — (CH ₂ ) _m1 —, more preferably an ethylene group or a methylene group, and even more preferably a methylene group.
R ² is preferably a fluorinated alkyl group, more preferably a fluorinated alkyl group having 1 to 6 carbon atoms.
Aromatic hydrocarbon groups include phenyl, naphthyl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, phenanthryl, 2 , 6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl, and the like.

Examples of the structural unit (I) include the following.

In the above structural unit, a structural unit in which a methyl group corresponding to R ¹ is replaced by a hydrogen atom can also be given as a specific example of the structural unit (I).

［式（Ｉ’）中、Ｒ^１、Ａ^１及びＲ^２は、上記と同じ意味を表す。］ The structural unit (I) is derived from a compound represented by the formula (I ′) (hereinafter sometimes referred to as “compound (I ′)”).

[In formula (I ′), R ¹ , A ¹ and R ² represent the same meaning as described above. ]

［式中、Ｒ^１、Ａ^１及びＲ^２は、上記と同じ意味を表す。］
式（Ｉ’−１）で表される化合物と式（Ｉ’−２）で表される化合物とを、溶媒中、触媒の存在下で反応させることが好ましい。溶媒としては、ジメチルホルムアミドなどが用いられる。触媒としては、炭酸カリウム及びヨウ化カリウムなどが用いられる。 Compound (I ′) can be produced, for example, by the following reaction.

[Wherein R ¹ , A ¹ and R ² represent the same meaning as described above. ]
It is preferable to react the compound represented by the formula (I′-1) and the compound represented by the formula (I′-2) in a solvent in the presence of a catalyst. As the solvent, dimethylformamide or the like is used. As the catalyst, potassium carbonate, potassium iodide and the like are used.

式（Ｉ’−３）で表される化合物は、Ａ¹の種類に応じて適当なものを用いることができる。
Ａ^１がメチレン基である場合の式（Ｉ’−２）で表される化合物は、式（Ｉ’−３）で表される化合物として、例えば、クロロアセチルクロリドなどを用いることにより製造することができる。このクロロアセチルクロリドは市場から容易に入手できる。
式（Ｉ’−４）で表される化合物は、Ｒ^２の種類に応じて適当なアルコールを用いることができる。
Ｒ^２がフッ素原子で置換された脂肪族炭化水素基である式（Ｉ’−２）で表される化合物は、式（Ｉ’−４）で表される化合物として、例えば、２，２，３，３，４，４，４−ヘプタフルオロ−１−ブタノールなどを用いることにより製造することができる。この２，２，３，３，４，４，４−ヘプタフルオロ−１−ブタノールは市場から容易に入手できる。 The compound represented by the formula (I′-1) is preferably a compound (commercially available) that can be easily obtained from the market. Such commercial products include methacrylic acid.
The compound represented by the formula (I′-2) is produced, for example, by reacting the compound represented by the formula (I′-3) with the compound represented by the formula (I′-4). Can do. This reaction is carried out in a solvent in the presence of a base catalyst. Tetrahydrofuran or the like is used as a solvent used in this reaction. As the base catalyst, pyridine or the like is used.

As the compound represented by the formula (I′-3), an appropriate compound can be used depending on the type of A ¹ .
The compound represented by the formula (I′-2) when A ¹ is a methylene group is produced by using, for example, chloroacetyl chloride as the compound represented by the formula (I′-3). Can do. This chloroacetyl chloride is readily available from the market.
As the compound represented by the formula (I′-4), an appropriate alcohol can be used depending on the type of R ² .
The compound represented by the formula (I′-2) in which R ² is an aliphatic hydrocarbon group substituted with a fluorine atom is, for example, 2,2, It can be produced by using 3,3,4,4,4-heptafluoro-1-butanol or the like. This 2,2,3,3,4,4,4-heptafluoro-1-butanol is readily available from the market.

［式（ＩＩＩＡ）中、
Ｒ^１１は、水素原子又はメチル基を表す。
環Ｗ^２は、炭素数６〜１０の炭化水素環を表す。
Ａ^１２は、−Ｏ−、^＊−ＣＯ−Ｏ−又は^＊−Ｏ−ＣＯ−（^＊は環Ｗ^１との結合手を表す。）を表す。
Ｒ^１２は、フッ素原子を有する炭素数１〜６のアルキル基を表す。］ The resin (A1) may have a structural unit different from the structural unit (I).
The structural unit different from the structural unit (I) includes a structural unit derived from the acid labile monomer (a1), a structural unit derived from the acid stable monomer (a4), and a structure represented by the formula (IIIA), which will be described later. Examples of the unit include structural units derived from known monomers used in the field. A structural unit represented by the formula (IIIA) is preferable.

[In the formula (IIIA),
R ¹¹ represents a hydrogen atom or a methyl group.
Ring ^{W 2} represents a hydrocarbon ring having 6 to 10 carbon atoms.
A ¹² represents —O—, ^* —CO—O—, or ^* —O—CO— ( ^* represents a bond to ring W ¹ ).
R ¹² represents a C 1-6 alkyl group having a fluorine atom. ]

Examples of the hydrocarbon ring of ring W ² include an alicyclic hydrocarbon ring, and a saturated alicyclic hydrocarbon ring is preferable.
Examples of the saturated alicyclic hydrocarbon ring include the following rings.

Ring W ² is preferably an adamantane ring or a cyclohexane ring, and more preferably an adamantane ring.
The alkyl group having 1 to 6 carbon atoms and having a fluorine atom in R ^12, for example, the following groups. ^* Represents a bond to ^{A 12.}

上記の構造単位において、Ｒ^１１に相当するメチル基が水素原子に置き換わった構造単位も、構造単位（ＩＩＩＡ）の具体例として挙げることができる。
中でも、式（ＩＩＩＡ−１）で表される構造単位又は当該構造単位におけるＲ^１１に相当するメチル基が水素原子に置き換わった構造単位が特に好ましい。 As the structural unit represented by the formula (IIIA), structural units represented by the following are preferable.

In the structural unit, a structural unit in which a methyl group corresponding to R ¹¹ is replaced with a hydrogen atom can also be given as a specific example of the structural unit (IIIA).
Among these, a structural unit represented by the formula (IIIA-1) or a structural unit in which a methyl group corresponding to R ¹¹ in the structural unit is replaced with a hydrogen atom is particularly preferable.

The content ratio of the structural unit (I) in the resin (A1) is more preferably in the range of 5 to 100 mol%, further preferably in the range of 10 to 100 mol%, based on all the structural units of the resin (A1). The range of 50 to 100 mol% is more preferable, and the range of 80 to 100 mol% is particularly preferable.
When the resin (A1) has the structural unit (IIIA), the content ratio of the structural unit (IIIA) in the resin (A1) ranges from 1 to 95 mol% with respect to all the structural units of the resin (A1). The range of 2 to 80 mol% is more preferable, the range of 5 to 70 mol% is more preferable, the range of 5 to 50 mol% is particularly preferable, and the range of 5 to 30 mol% is particularly preferable. When the structural unit (IIIA) is included and the content ratio is within the above range, a resist pattern having an excellent focus margin and few defects can be manufactured.
Resin (A1) having structural units (I) and / or (IIIA) in such a content ratio is compound (I ′), structural unit (IIIA) relative to the total molar amount of all monomers used in the production of resin (A1). It can be produced by adjusting the molar amount of the monomer used for deriving.
Each structural unit (I) and / or (IIIA) constituting the resin (A1) may be one kind or a combination of two or more kinds, and optionally, an acid stable monomer (a1), an acid stable monomer, which will be described later, It can be produced by a known polymerization method (for example, radical polymerization method) by combining one or more monomers known in the art.
The weight average molecular weight of the resin (A1) is preferably 5,000 or more (more preferably 7,000 or more, more preferably 10,000 or more), 80,000 or less (more preferably 50,000 or less, further preferably Is 30,000 or less). A weight average molecular weight is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis, and the detailed analysis conditions of this analysis are explained in full detail in the Example of this application.

<Resin (A2)>
The resin (A2) is a resin having an acid labile group. The resin having an acid labile group is derived from one or more monomers having an acid labile group (hereinafter sometimes referred to as “acid labile monomer (a1)”).
In addition, the resin (A2) is a structural unit derived from a monomer having no acid labile group, which will be described later (hereinafter sometimes referred to as “acid stable monomer”), as long as it has the acid labile group described above. The structural unit derived from a known monomer, the structural unit represented by the structural unit (I) and the formula (IIIA) described above may be included.
The resin (A2) may be a resin different from the resin (A1), or has a structural unit represented by the formula (I) and a structural unit represented by the formula (IIIA). Further, it may be a resin having an acid labile group.

<Acid labile monomer (a1)>
The acid labile monomer (a1) is a monomer having at least an acid labile group. Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2).

［式（１）中、Ｒ^a1〜Ｒ^a3は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜２０の脂環式炭化水素基を表すか、Ｒ^a1及びＲ^a2は互いに結合して炭素数２〜２０の２価の炭化水素基を形成する。＊は結合手を表す。］

［式（２）中、Ｒ^a1'及びＲ^a2'は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^a3'は、炭素数１〜２０の炭化水素基を表すか、Ｒ^a2'及びＲ^a3'は互いに結合して炭素数２〜２０の２価の炭化水素基を形成し、前記炭化水素基及び前記２価の炭化水素基に含まれる−ＣＨ_２−は、−Ｏ―又は―Ｓ−で置き換わってもよい。＊は結合手を表す。］

In Expression (1), R ^a1 ~R ^a3 each independently represent a cycloaliphatic hydrocarbon radical of the alkyl group or 3 to 20 carbon atoms having 1 to 8 carbon atoms, R ^a1 and R ^a2 are each Bonding to form a divalent hydrocarbon group having 2 to 20 carbon atoms. * Represents a bond. ]

[In Formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group. May be replaced by -O- or -S-. * Represents a bond. ]

アルキル基で置換された脂環式炭化水素基としては、例えば、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基等が挙げられる。
式（１）においては、Ｒ^a1〜Ｒ^a3の脂環式炭化水素基は、好ましくは炭素数３〜１６である。 ^Examples of the alkyl group represented by R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an alkyl group. In this case, the carbon number of the alicyclic hydrocarbon group is 20 or less including the carbon number of the alkyl group.
Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond).

Examples of the alicyclic hydrocarbon group substituted with an alkyl group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
In Formula (1), the alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 3 to 16 carbon atoms.

Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group include the following groups. The divalent hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

Examples of the acid labile group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), groups in which R ^{a1 to} R ^a3 are alkyl groups, preferably tert-butoxycarbonyl). Group), 2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and a carbon atom form an adamantyl group, and R ^a3 is an alkyl group) and 1- (adamantane) -1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

Examples of the hydrocarbon group for R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.
Examples of the alkyl group and alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the divalent hydrocarbon group formed by combining R ^{a2 ′} and R ^{a3 ′} include a divalent aliphatic hydrocarbon group.
In Formula (2), it is preferable that at least one of R ^{a1 ′} and R ^{a2 ′} is a hydrogen atom.
Specific examples of the group represented by the formula (2) include the following groups. * Represents a bond.

  The acid labile monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, more preferably a (meth) acrylic monomer having an acid labile group.

  Among the (meth) acrylic monomers having an acid labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. If a resin obtained by polymerizing an acid labile monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used, the resolution of the resist pattern can be improved.

  The (meth) acrylic monomer having an acid labile group and an alicyclic hydrocarbon group is preferably a monomer for deriving a structural unit represented by formula (a1-1) or represented by formula (a1-2). And a monomer that induces a structural unit. These may be used alone or in combination of two or more. In this specification, the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2) are represented by the structural unit (a1-1) and the structural unit (a1-2), respectively. The monomer that derives the structural unit (a1-1) and the monomer that derives the structural unit (a1-2) may be referred to as a monomer (a1-1) and a monomer (a1-2), respectively.

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−を表し、ｋ１は１〜７の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜１０の脂環式炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ１’は０〜３の整数を表す。］

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

L ^a1 and L ^a2 are preferably —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, more preferably —O—. k1 is preferably an integer of 1 to 4, more preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
^Examples of the alkyl group for R ^a6 and R ^a7 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group for R ^a6 and R ^a7 may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an alkyl group. . In this case, the carbon number of the alicyclic hydrocarbon group is 10 or less including the carbon number of the alkyl group. Specific examples include the same groups as the alicyclic hydrocarbon groups represented by R ^{a1 to} R ^{a3 in} the formula (1).
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As a monomer (a1-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Monomers respectively represented by formula (a1-1-1) to formula (a1-1-8) are preferred, and monomers represented by formula (a1-1-1) to formula (a1-1-4) are preferred. More preferred.

Examples of the monomer (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethylcycloheptan-1-yl (meth). Examples include acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, and 1-isopropylcyclopentan-1-yl (meth) acrylate. Monomers respectively represented by formula (a1-2-1) to formula (a1-2-12) are preferred, and are represented by formula (a1-2-3), formula (a1-2-4), and formula (a1-2-2). 9) and monomers represented by formula (a1-2-10) are more preferred, and monomers represented by formula (a1-2-3) and formula (a1-2-9) are more preferred.

  When resin (A2) contains structural unit (a1-1) and / or structural unit (a1-2), these total content rates are 10-95 mol normally with respect to all the structural units of resin (A2). %, Preferably 15 to 90 mol%, more preferably 20 to 85 mol%.

式（ａ１−５）中、
Ｒ^３１は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｌ^１１〜Ｌ^１３は、酸素原子、硫黄原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−で表される基を表す。ここで、ｋ１は１〜７の整数を表し、＊はカルボニル基（−ＣＯ−）との結合手である。
Ｚ^１は、単結合又は炭素数１〜６のアルカンジイル基であり、該アルカンジイル基中に含まれるメチレン基は、オキシ基又はカルボニル基に置き換わっていてもよい。
ｓ１及びｓ１’は、それぞれ独立して、０〜４の整数を表す。 Examples of the other acid labile monomer (a1) include a monomer represented by the formula (a1-5) which is a (meth) acrylic monomer having an acid labile group (2) (hereinafter referred to as “monomer (a1-5)”. ) ”May be used.

In formula (a1-5),
R ³¹ represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
L ^{11 to} L ¹³ represent an oxygen atom, a sulfur atom, or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O—. Here, k1 represents an integer of 1 to 7, and * is a bond with a carbonyl group (—CO—).
Z ¹ is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group contained in the alkanediyl group may be replaced with an oxy group or a carbonyl group.
s1 and s1 ′ each independently represents an integer of 0 to 4.

In formula (a1-5), R ³¹ is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ¹¹ is preferably an oxygen atom.
One of L ¹² and L ¹³ is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ¹ is preferably a single bond or —CH ₂ —CO—O—.

Examples of the monomer (a1-5) include the following monomers.

  When the resin (A2) has a structural unit derived from the monomer (a1-5), the content thereof is preferably in the range of 1 to 50 mol% with respect to all the structural units of the resin (A2). The range of 45 mol% is more preferable, and the range of 5 to 40 mol% is more preferable.

<Acid stable monomer>
As an acid stable monomer, Preferably, the monomer which has a hydroxyl group or a lactone ring is mentioned. Acid-stable monomer having a hydroxy group (hereinafter sometimes referred to as “acid-stable monomer having a hydroxy group (a2)”) or acid-stable monomer having a lactone ring (hereinafter referred to as “acid-stable monomer having a lactone ring (a3)”) If a resin having a structural unit derived from (sometimes) is used, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Acid-stable monomer having a hydroxy group (a2)>
When the resist composition is used for KrF excimer laser exposure (248 nm), high energy beam exposure such as electron beam or EUV light, the acid-stable monomer (a2) having a hydroxy group is preferably a phenolic hydroxy which is a hydroxystyrene. An acid-stable monomer having a group is used. When using short-wavelength ArF excimer laser exposure (193 nm) or the like, the acid-stable monomer (a2) having a hydroxy group is preferably an acid-stable monomer having a hydroxyadamantyl group represented by the formula (a2-1). use. The acid-stable monomer (a2) having a hydroxy group may be used alone or in combination of two or more.

式（ａ２−１）中、
Ｌ^a3は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−を表し、
ｋ２は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。 Examples of the acid stable monomer having a hydroxyadamantyl group include a monomer represented by the formula (a2-1).

In formula (a2-1),
L ^a3 represents —O— or ^* —O— (CH ₂ ) _k2 —CO—O—,
k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10.

In the formula (a2-1), L ^a3 is preferably, -O -, - O- (CH 2) f1 -CO-O- and is (wherein f1 is an integer from 1 to 4), more preferably Is —O—.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

As an acid stable monomer (a2-1) which has a hydroxyadamantyl group, the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Monomers respectively represented by formula (a2-1-1) to formula (a2-1-6) are preferred, and monomers represented by formula (a2-1-1) to formula (a2-1-4) are preferred. More preferred is a monomer represented by formula (a2-1-1) or formula (a2-1-3).

  When the resin (A2) contains a structural unit derived from the monomer represented by the formula (a2-1), the content is usually 1 to 45 mol% with respect to all the structural units of the resin (A2). , Preferably it is 1-40 mol%, More preferably, it is 2-35 mol%.

<Acid-stable monomer having a lactone ring (a3)>
The lactone ring possessed by the acid stable monomer (a3) may be, for example, a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, and a monocyclic lactone ring and other rings The condensed ring may be used. Among these lactone rings, a γ-butyrolactone ring or a condensed ring of γ-butyrolactone ring and another ring is preferable.

  The acid-stable monomer (a3) having a lactone ring is preferably represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3). These 1 type may be used independently and may use 2 or more types together.

式（ａ３−１）〜式（ａ３−３）中、
Ｌ^a4〜Ｌ^a6は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−を表す。
ｋ３は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a18〜Ｒ^a20は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a21は、炭素数１〜４のアルキル基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a22及びＲ^a23は、それぞれ独立に、カルボキシ基、シアノ基又は炭素数１〜４のアルキル基を表す。
ｑ１及びｒ１は、それぞれ独立に０〜３の整数を表す。ｐ１、ｑ１又はｒ１が２以上のとき、それぞれ、複数のＲ^a21、Ｒ^a22又はＲ^a23は、同一又は相異なる。

In formula (a3-1) to formula (a3-3),
L ^{a4 to} L ^a6 each independently represent —O— or ^* —O— (CH ₂ ) _k3 —CO—O—.
k3 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents an alkyl group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or an alkyl group having 1 to 4 carbon atoms.
q1 and r1 each independently represents an integer of 0 to 3. When p1, q1 or r1 is 2 or more, a plurality of R ^a21 , R ^a22 or R ^a23 are the same or different, respectively.

^Examples of the alkyl group represented by R ^{a21 to} R ^a23 include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, and a sec-butyl group.

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 are preferably each independently —O— or ^* —O— (CH ₂ ) _k3 —CO—O—, More preferably, it is -O-. k3 is preferably an integer of 1 to 4, more preferably 1.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1 to r1 are each independently preferably 0 to 2, more preferably 0 or 1.

  Examples of the acid-stable monomer (a3) having a lactone ring include monomers described in JP 2010-204646 A. Formula (a3-1-1) to Formula (a3-1-4), Formula (a3-2-1) to Formula (a3-2-4), Formula (a3-3-1) to Formula (a3-3) -4) is preferred, and each represented by formula (a3-1-1), formula (a3-1-2), formula (a3-2-3), or formula (a3-2-4) The monomer represented is more preferable, and the monomer represented by the formula (a3-1-1) or the formula (a3-2-3) is more preferable.

  When the resin (A2) includes a structural unit derived from the acid-stable monomer (a3) having a lactone ring, the total content is usually 5 to 70 mol% with respect to all the structural units of the resin (A2). , Preferably it is 10-65 mol%, More preferably, it is 10-60 mol%.

When the resin (A2) is a copolymer of an acid labile monomer (a1) and an acid stable monomer, the structural unit derived from the acid labile monomer (a1) is based on 100 mol% of all structural units. Preferably it is 10-80 mol%, More preferably, it is 20-60 mol%.
The content of the structural unit derived from the monomer having an adamantyl group (particularly the structural unit (a1-1)) is preferably 15 mol% or more based on the total of the structural units derived from the acid labile monomer (a1). is there. When the ratio of the structural unit derived from the monomer having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

  The resin (A2) is preferably a copolymer of an acid labile monomer (a1) and an acid stable monomer. In this copolymer, the acid labile monomer (a1) is more preferably at least one of the monomer (a1-1) having an adamantyl group and the monomer (a1-2) (preferably the monomer having a cyclohexyl group or a cyclopentyl group). One type, more preferably monomer (a1-1). The acid stable monomer is preferably an acid stable monomer (a2) having a hydroxy group and / or an acid stable monomer (a3) having a lactone ring. The acid-stable monomer (a2) having a hydroxy group is preferably an acid-stable monomer (a2-1) having a hydroxyadamantyl group, and the acid-stable monomer (a3) having a lactone ring is more preferably a γ-butyrolactone ring. The acid-stable monomer (a3-1) and the acid-stable monomer (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring.

Each structural unit constituting the resin (A2) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do.
The weight average molecular weight of the resin (A2) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 4,000 or more), 50,000 or less (more preferably 30,000 or less, further preferably 15,000 or less).
Resin (A1) and resin (A2) in resin (A) are, for example, 0.01: 10 to 5:10, preferably 0.05: 10 to 3:10, more preferably 0.1: 10. It is preferable that it is contained at 2:10, particularly preferably 0.2: 10 to 1:10 (mass ratio).

<Resin other than resin (A1) and (A2)>
The resin (A) of the resist composition of the present invention is derived from resins other than the resins (A1) and (A2) described above, for example, structural units derived from the acid labile monomer (a1) described above, and acid stable monomers. In addition to the structural unit, a resin composed of a structural unit derived from a known monomer used in this field may be contained.
When the resist composition of this invention contains resin other than resin (A1) and (A2), these content rates are normal with respect to the total amount of resin (A) contained in the resist composition of this invention. It is 0.1-50 mass%, Preferably it is 0.5-30 mass%, More preferably, it is 1-20 mass%.

  In the resist composition of the present invention, the content of the resin (A) is preferably 80% by mass or more and 99% by mass or less in the solid content of the resist composition. In the present specification, the “solid content in the composition” means the total of resist composition components excluding the solvent (E) described later. The solid content in the composition and the content of the resin (A) relative thereto can be measured, for example, by a known analysis means such as liquid chromatography or gas chromatography.

［式（ＩＩ）中、
Ｑ^１及びＱ^２は、互いに独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^１は、２価の炭素数１〜１７の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。
環Ｗは、炭素数３〜３６の脂環式炭化水素環を表し、該脂環式炭化水素環に含まれるメチレン基は、酸素原子、硫黄原子、カルボニル基又はスルホニル基で置換されていてもよく、該脂環式炭化水素環に含まれる水素原子は、水酸基、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、炭素数３〜１２の脂環式炭化水素基又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。
Ｒ^ｆ１及びＲ^ｆ２は、互いに独立に、フッ素原子又は炭素数１〜６のフッ化アルキル基を表す。
ｓは、１〜１０の整数を表し、ｓが２以上の場合、複数のＲ^ｆ１及びＲ^ｆ２はそれぞれ同一又は相異なる。
Ｚ^＋は、有機カチオンを表す。］
式（ＩＩ）において、正電荷を有するＺ^＋で示される有機カチオンを除去してなる負電荷を有するものを「スルホン酸アニオン」ということがある。 <Acid generator (II)>
The acid generator (II) contained in the resist composition of the present invention contains a salt represented by the formula (II).

[In the formula (II),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon ring may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. Well, the hydrogen atom contained in the alicyclic hydrocarbon ring is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or carbon. The aromatic hydrocarbon group of several 6-10 may be substituted.
R ^f1 and R ^f2 each independently represent a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
s represents an integer of 1 to 10, and when s is 2 or more, the plurality of R ^f1 and R ^f2 are the same or different.
Z ⁺ represents an organic cation. ]
In the formula (II), those having a negative charge obtained by removing an organic cation represented by Z ⁺ having a positive charge may be referred to as “sulfonate anion”.

Examples of the C 1-6 perfluoroalkyl group represented by Q ¹ and Q ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, A perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group and the like can be mentioned.
Q ¹ and Q ² are preferably each independently a trifluoromethyl group or a fluorine atom, and more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ¹ include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and these A combination of two or more of the groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group;
An alkyl group (particularly an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group); For example, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4 A branched alkanediyl group such as a diyl group or 2-methylbutane-1,4-diyl group;
Cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,2-diyl group, 1-methylcyclohexane-1,2-diyl group, cyclohexane-1,4-diyl group, cyclo A monocyclic divalent alicyclic saturated hydrocarbon group which is a cycloalkanediyl group such as an octane-1,2-diyl group or a cyclooctane-1,5-diyl group;
A polycyclic group such as norbornane-2,3-diyl group, norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. A bivalent alicyclic saturated hydrocarbon group etc. are mentioned.
The divalent alicyclic hydrocarbon group may be a group obtained by removing any one hydrogen atom from a monovalent alicyclic hydrocarbon group described later.

Examples of the group in which the methylene group in the saturated hydrocarbon group represented by L ¹ is replaced by an oxygen atom or a carbonyl group include groups represented by any of the following formulas (b1-1) to (b1-7): Is mentioned. Expressions (b1-1) to (b1-7) are described in accordance with Expression (II) on the left and right, and of the two bonds indicated by *, the left bond is C (Q ¹ ) It is bonded to the carbon atom of (Q ² ). The same applies to specific examples of the following formulas (b1-1) to (b1-7).

式（ｂ１−１）〜式（ｂ１−７）中、
Ｌ^b2は、単結合又は炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２の２価の飽和炭化水素基を表す。
Ｌ^b4は、炭素数１〜１３の２価の飽和炭化水素基を表す。但しＬ^b3及びＬ^b4の合計炭素数の上限は１３である。
Ｌ^b5は、炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b6は、単結合又は炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b7は、炭素数１〜１５の２価の飽和炭化水素基を表す。但しＬ^b6及びＬ^b7の合計炭素数の上限は１６である。
Ｌ^b8は、炭素数１〜１４の２価の飽和炭化水素基を表す。
Ｌ^b9は、単結合又は炭素数１〜１１の２価の飽和炭化水素基を表す。Ｌ^b10は、炭素数１〜１２の２価の飽和炭化水素基を表す。但しＬ^b9及びＬ^b10の合計炭素数の上限は１２である。
Ｌ^b11及びＬ^b12は、それぞれ独立に、単結合又は炭素数１〜１４の飽和炭化水素基を表す。但しＬ^b11及びＬ^b12の合計炭素数の上限は１４である。

In formula (b1-1) to formula (b1-7),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b7 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b9 represents a single bond or a divalent saturated hydrocarbon group having 1 to 11 carbon atoms. L ^b10 represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12.
L ^b11 and L ^b12 each independently represent a single bond or a saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b11 and L ^b12 is 14.

L ¹ is preferably a group represented by any one of formulas (b1-1) to (b1-5), more preferably any one of formulas (b1-1) to (b1-4). A group represented by formula (b1-1) or formula (b1-3), particularly preferably a divalent group represented by formula (b1-1). is there. Among them, preferably, L ^b2 in the formula (b1-1) is a single bond or a saturated hydrocarbon group having 1 to 6 carbon atoms, and more preferably * —CO—O— (CH ₂ ) _t — (t is Represents an integer of 0 to 6. * represents a bond to —C (Q ¹ ) (Q ² ) —, and more preferably, a formula (b1—) wherein L ^b2 is a single bond or a methylene group. A divalent group represented by 1), particularly preferably a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond, that is, * —CO—O—.

Examples of the divalent group represented by the formula (b1-1) include the following.

Examples of the divalent group represented by the formula (b1-2) include the following.

Examples of the divalent group represented by the formula (b1-3) include the following.

Examples of the divalent group represented by the formula (b1-4) include the following.

Examples of the divalent group represented by the formula (b1-5) include the following.

Examples of the divalent group represented by the formula (b1-6) include the following.

Examples of the divalent group represented by the formula (b1-7) include the following.

なかでも、環Ｗは、式（ＩＩａ１−１）で表される環、式（ＩＩａ１−２）で表される環又は式（ＩＩａ１−３）で表される環が好ましい。

［式（ＩＩａ１−１）、式（ＩＩａ１−２）及び式（ＩＩａ１−３）中、
環に含まれるメチレン基は酸素原子、硫黄原子、カルボニル基又はスルホニル基で置換されていてもよく、環に含まれる水素原子は、水酸基、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、炭素数３〜１２の脂環式炭化水素基又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。］ The alicyclic hydrocarbon ring having 3 to 36 carbon atoms in the ring W may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon ring include cyclopentane and cyclohexene. Examples include cycloalkane rings such as xane, methylcyclohexane, dimethylcyclohexane, cycloheptane, and cyclooctane ring. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthalene, adamantane, norbornane, methylnorbornane ring, and the following rings.

Among these, the ring W is preferably a ring represented by the formula (IIa1-1), a ring represented by the formula (IIa1-2), or a ring represented by the formula (IIa1-3).

[In Formula (IIa1-1), Formula (IIa1-2) and Formula (IIa1-3),
The methylene group contained in the ring may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group, and the hydrogen atom contained in the ring is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms. May be substituted with an alkoxy group, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms. ]

As the alkyl group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group And cyclooctyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentoxy group, n-hexoxy group and the like. .
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group, mesityl group. , Aryl groups such as biphenyl group, anthryl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.

In the ring W described above, the position of the bond between L ¹ and two oxygen atoms can be any position. Among them, in the ring represented by the formula (IIa1-1), the ring represented by the formula (IIa1-2) or the ring represented by the formula (IIa1-3), the bond * is the following position. Those are preferred.

Examples of the fluorinated alkyl group for R ^f1 and R ^f2 include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, and a 2,2,2-trifluoroethyl group. Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl)- 1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1, 1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (per Fluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5 -Decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1 , 2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group Perfluoropentylmethyl group and perfluorohexyl group. Of these, a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, and the like are preferable.
R ^f1 and R ^f2 are preferably fluorine atoms.

が、以下の基であるものが特に好ましい。

s is preferably an integer of 1 to 8, more preferably an integer of 1 to 6, more preferably an integer of 1 to 4, or a ring containing 1 or 2, that is, —O—C—O—.

However, those having the following groups are particularly preferred.

Specific examples of the sulfonate anion of the acid generator of formula (II) include the following.

Examples of the organic cation represented by Z ⁺ include an organic onium cation such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an arylsulfonium cation is more preferable.

More preferably, for example, Formula (Z1) to Formula (Z4) are included.

In formula (Z1) to formula (Z4),
Do P ^{a to} P ^c each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms? , P ^a and P ^b may together form a ring containing a sulfur atom. The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or It may be substituted with an alkoxy group having 1 to 12 carbon atoms.

P ⁴ and P ⁵ each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
P ⁶ and P ⁷ each independently represent an aliphatic hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or P ⁶ and P ^{7 taken} together Forms a ring containing a sulfur atom to which.
P ⁸ represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
P ⁹ represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the aromatic hydrocarbon group may be an alkoxy group having 1 to 12 carbon atoms or a carbon atom. The alkylcarbonyloxy group of Formula 1-12 may be substituted.
P ⁸ and P ⁹ may be combined to form a ring containing —CH—CO— to which they are attached.

P < ¹⁰ > -P < ¹⁵ > represents a hydroxyl group, a C1-C12 aliphatic hydrocarbon group, or a C1-C12 alkoxy group each independently.
E represents -S- or -O-.
i, j, p, r, x and y each independently represents an integer of 0 to 5;
q represents 0 or 1;
v and w each independently represent an integer of 0 to 4.
When i is 2 or more, the plurality of P ⁴ are the same or different from each other, when j is 2 or more, the plurality of P ⁵ are the same or different from each other, and when p is 2 or more, the plurality of P ¹⁰ are When r is 2 or more, the plurality of P ¹¹ are the same or different from each other, when v is 2 or more, the plurality of P ¹² are the same or different from each other, and when w is 2 or more, P ¹³ is the same or different from each other. When x is 2 or more, the plurality of P ¹⁴ are the same or different from each other. When y is 2 or more, the plurality of P ¹⁵ are the same or different from each other.

水素原子が脂肪族炭化水素基で置換された脂環式炭化水素基としては、例えば、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基、２−アルキルアダマンタン−２−イル基、メチルノルボルニル基、イソボルニル基等が挙げられる。
芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ｐ−メチルフェニル基、ｐ−ｔｅｒｔ−ブチルフェニル基、ｐ−アダマンチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、ビフェニル基、フェナントリル基、２，６−ジエチルフェニル基、２−メチル−６−エチルフェニル等のアリール基等が挙げられる。
なお、芳香族炭化水素基に、脂肪族炭化水素基又は脂環式炭化水素基が含まれる場合は、炭素数１〜１８の脂肪族炭化水素基及び炭素数３〜１８の脂環式炭化水素基が好ましい。 Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Is mentioned.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include an aralkyl group, and specifically include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. Groups and the like.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and dimethylcyclohexane. Examples thereof include a cycloalkyl group such as a hexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, a methylnorbornyl group, and the following groups. * Represents a bond with an adamantane ring or a cyclohexane ring.

Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a 2-alkyladamantan-2-yl group, and a methyl group. A norbornyl group, an isobornyl group, etc. are mentioned.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
When the aromatic hydrocarbon group includes an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, the aliphatic hydrocarbon group having 1 to 18 carbon atoms and the alicyclic hydrocarbon having 3 to 18 carbon atoms Groups are preferred.

As an alkoxy group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentoxy group, an n-hexoxy group, a heptoxy group, an octoxy group , 2-ethylhexoxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group and the like.
As an aromatic hydrocarbon group by which the hydrogen atom was substituted by the alkoxy group, 4-methoxyphenyl group etc. are mentioned, for example.
Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

Examples of the ring and the P ^a and P ^b together form a monocyclic, polycyclic, aromatic or non-aromatic, it may be any of the rings of the saturated and unsaturated, sulfur atom In addition, one or more sulfur atoms and / or one or more oxygen atoms, that is, —O—, —S—, or —CO— may be further included. This ring includes a 3-membered ring to a 18-membered ring, preferably a 3-membered ring to a 12-membered ring or a 4- to 18-membered ring.
The ring formed by combining P ⁶ and P ⁷ may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings, and a sulfur atom If it contains one or more, it may further contain one or more sulfur atoms and / or one or more oxygen atoms, that is, —O—, —S—, or —CO—. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring.
The ring formed by combining P ⁸ and P ⁹ may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated, and —CH— As long as it contains CO-, it may further contain one or more sulfur atoms and / or one or more oxygen atoms, that is, -O-, -S-, -CO-. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring.

Examples of the ring formed together with the sulfur atom to which P ⁶ and P ⁷ are bonded include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. Etc.
Examples of the ring formed with —CH—CO— to which P ⁸ and P ⁹ are bonded include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Among the cations represented by the formulas (Z1) to (Z4), the formula (Z1) is preferable, the cation represented by the formula (Z5) is more preferable, and the triphenylsulfonium cation (in the formula (Z5), z1 = z2 = z3 = 0), in diphenyl tolyl sulfonium cation (formula (Z5), a z1 = z2 = 0, z3 = 1, P 3 is a methyl group.) or tri tolyl sulfonium cation (formula (Z5) in Z1 = z2 = z3 = 1 and P ¹ , P ² and P ³ are all methyl groups.

式（Ｚ５）中、
Ｐ^１〜Ｐ^３は、それぞれ独立に、ハロゲン原子、ヒドロキシ基、炭素数１〜１８の脂肪族炭化水素基、炭素数３〜１８の脂環式炭化水素基又は炭素数１〜１２のアルコキシ基を表すか、Ｐ^１〜Ｐ^３から選ばれる２つが一緒になってヘテロ原子を有してもよい環を形成してもよい。
ｚ１、ｚ２及びｚ３は、それぞれ独立に、０〜５の整数を表す。ｚ１、ｚ２及びｚ３のいずれかが２以上のとき、複数のＰ^１、Ｐ^２、Ｐ^３は、それぞれ、同一又は相異なる。

In formula (Z5),
P ^{1 to} P ³ are each independently a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. Or two selected from P ^{1 to} P ³ may be combined to form a ring that may have a hetero atom.
z1, z2 and z3 each independently represents an integer of 0 to 5. When any of z1, z2 and z3 is 2 or more, the plurality of P ¹ , P ² and P ³ are the same or different from each other.

The ring formed by combining two selected from P ^{1 to} P ³ may be any of monocyclic, polycyclic, aromatic and non-aromatic rings. As long as it contains the above, it may contain one or more sulfur atoms and / or one or more oxygen atoms.
Aliphatic hydrocarbon group of P ¹ to P ³ is preferably 1 to 12 carbon atoms, alicyclic hydrocarbon group is preferably 4 to 18 carbon atoms.
Among them, each of P ^{1 to} P ³ independently represents a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, or P ¹ two selected from to P ³ is represent together -O-, it is preferable to form a ring containing a sulfur atom. Each z is independently preferably 0 or 1.

Examples of the cation represented by the formula (Z1) or the formula (Z5) include the following.

The following are mentioned as a specific example of the cation in which the ring containing a sulfur atom was formed among the cations represented by a formula (Z5).

Specific examples of the cation (Z1) include the following.

Specific examples of the cation (Z2) include the following.

Specific examples of the cation (Z3) include the following.

Specific examples of the cation (Z4) include the following.

  The salt represented by the formula (II) is a combination of the above-mentioned anion and organic cation. Although the above-mentioned anion and cation can be combined arbitrarily, the compound represented below is preferable. In the following formulae, the definition of the substituent has the same meaning as described above.

Examples of the salt represented by the formula (II) include the following compounds.

（式中、Ｑ^１、Ｑ^２、Ｗ、Ｒ^ｆ１、Ｒ^ｆ２、ｓ及びＺ^＋は、それぞれ上記と同義である。） The manufacturing method of the compound represented by Formula (b1) among the salts represented by Formula (II) is shown below.

(In the formula, Q ¹ , Q ² , W, R ^f1 , R ^f2 , s and Z ⁺ are as defined above.)

First, a salt represented by the formula (b1) is prepared by reacting a salt represented by the formula (b1-a) with a compound represented by the formula (b1-b) in a solvent under an acid catalyst condition. Get. Examples of the solvent include 1,2-dichloroethane. Examples of the catalyst include p-toluenesulfonic acid.

The salt represented by the formula (b1-a) can be synthesized, for example, by the method described in JP2007-224008A.
Examples of the compound represented by the formula (b1-b) include 2,2,3,3-tetrafluoro-1,4-butanediol.

The salt represented by the formula (II) may be used alone or in combination of two or more.
Moreover, the acid generator may contain acid generators other than the salt represented by the formula (II) described above.

<Acid generator (B)>
The resist composition of the present invention contains a known acid generator (hereinafter sometimes referred to as “acid generator (B)”) in addition to the acid generator containing the salt represented by the formula (II). Also good.
The acid generator (B) is classified into a nonionic type and an ionic type, and any of them may be used in the resist composition of the present invention. Examples of the nonionic acid generator include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) and the like. Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator (B) include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP 62-153853, JP 63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. The compound which generate | occur | produces an acid by the radiation as described in etc. can be used.

  The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a sulfonate represented by the formula (B1).

［式（Ｂ１）中、
Ｑ^b1及びＱ^b2は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、単結合又は２価の炭素数１〜１７の飽和炭化水素基を表し、前記２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、前記アルキル基及び前記脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよい。
Ｚ１⁺は、有機カチオンを表す。］

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. May be.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the alkyl group and the above —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z1 ⁺ represents an organic cation. ]

^Examples of Q ^b1 and Q ^b2 in formula (B1) include the same as Q ¹ and Q ² in formula (II).
Q ^b1 and Q ^b2 are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and among these groups, Two or more types may be combined.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
An alkyl group (particularly an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group); For example, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4 A branched alkanediyl group such as a diyl group or 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced by —O— or —CO— include those represented by formulas (b1-1 ′) to (b1-7 ′). Can be mentioned. In addition, Formula (b1-1 ')-Formula (b1-7') have described the right and left according to Formula (B1), and it is C on the left side among two bonds represented by *, respectively. It binds to (Q ^b1 ) (Q ^b2 ) — and on the right side to —Y. The same applies to specific examples of the following formulas (b1-1 ′) to (b1-7 ′).

式（ｂ１−１’）〜式（ｂ１−７’）中、
Ｌ^b2’は、単結合又は炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b3’は、単結合又は炭素数１〜１２の２価の飽和炭化水素基を表す。
Ｌ^b4’は、炭素数１〜１３の２価の飽和炭化水素基を表す。但しＬ^b3’及びＬ^b4’の炭素数上限は１３である。
Ｌ^b5’は、炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b6’及びＬ^b7’は、それぞれ独立に、炭素数１〜１５の２価の飽和炭化水素基を表す。但しＬ^b6’及びＬ^b7’の炭素数上限は１６である。
Ｌ^b8’は、炭素数１〜１４の２価の飽和炭化水素基を表す。
Ｌ^b9’及びＬ^b10’は、それぞれ独立に、炭素数１〜１１の２価の飽和炭化水素基を表す。但しＬ^b9’及びＬ^b10’の炭素数上限は１２である。
Ｌ^b11'及びＬ^b12'は、それぞれ独立に、単結合又は炭素数１〜１４の飽和炭化水素基を表す。但しＬ^b11'及びＬ^b12'の合計炭素数の上限は１４である。
中でも、Ｌ^b1は、好ましくは式（ｂ１−１’）〜式（ｂ１−４’）のいずれか、より好ましくは式（ｂ１−１’）又は式（ｂ１−２’）、さらに好ましくは式（ｂ１−１’）で表される２価の基であり、より好ましくは、Ｌ^b2’が単結合又は−ＣＨ_２−である式（ｂ１−１’）で表される２価の基である。

In formula (b1-1 ′) to formula (b1-7 ′),
L ^{b2 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^{b3 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^{b4 ′} represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the carbon number of L ^{b3 ′} and L ^{b4 ′} is 13.
L ^{b5 ′} represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^{b6 ′} and L ^{b7 ′} each independently represent a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the carbon number of L ^{b6 ′} and L ^{b7 ′} is 16.
L ^{b8 ′} represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^{b9 ′} and L ^{b10 ′} each independently represent a divalent saturated hydrocarbon group having 1 to 11 carbon atoms. However, the upper limit of the carbon number of L ^{b9 ′} and L ^{b10 ′} is 12.
L ^{b11 ′} and L ^{b12 ′} each independently represent a single bond or a saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^{b11 ′} and L ^{b12 ′} is 14.
Among them, L ^b1 is preferably any one of formula (b1-1 ′) to formula (b1-4 ′), more preferably formula (b1-1 ′) or formula (b1-2 ′), and more preferably formula (b1-1 ′). A divalent group represented by (b1-1 ′), more preferably a divalent group represented by the formula (b1-1 ′) in which L ^{b2 ′} is a single bond or —CH ₂ —. is there.

Examples of the divalent group represented by formula (b1-1 ′) to formula (b1-5 ′) and formula (b1-7 ′) include the formula (b1-1) to formula (b1-5) and The thing similar to the bivalent group of a formula (b1-7) is mentioned.
Examples of the divalent group represented by the formula (b1-6 ′) include the following in addition to the divalent group represented by the formula (b1-6).

Examples of the alkyl group for Y include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, heptyl group, 2 -Alkyl groups, such as an ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, are mentioned, Preferably, a C1-C6 alkyl group is mentioned.
Examples of the alicyclic hydrocarbon group include groups represented by the following formulas (Y1) to (Y11).
Examples of the group in which —CH ₂ — contained in the alicyclic hydrocarbon group of Y is replaced by —O—, —SO ₂ — or —CO— are represented by formulas (Y12) to (Y26). Groups.

  Especially, it is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

Examples of the substituent of the alkyl group and alicyclic hydrocarbon group in Y include, for example, a halogen atom, a hydroxy group, an oxo group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, carbon C3-C16 alicyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 aromatic hydrocarbon group, C7-C21 aralkyl group, C2-C4 acyl group , Glycidyloxy group or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or carbon Represents an aromatic hydrocarbon group of formula 6 to 18. j2 represents an integer of 0 to 4. The alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, aralkyl group, and the like, which are substituents for Y, may further have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxy group, and an oxo group.

Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group, mesityl group. , Aryl groups such as biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group.
Examples of the acyl group include acetyl, propionyl, butyryl and the like.

Examples of Y include the following.

When Y is an alkyl group and L ^b1 is a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms, the methylene group of the divalent aliphatic hydrocarbon group bonded to Y is oxygen It is preferably replaced by an atom or a carbonyl group. In this case, the methylene group constituting the alkyl group of Y is not replaced with an oxygen atom or a carbonyl group.

  Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, more preferably a substituent (for example, an oxo group, a hydroxy group, etc.). A good adamantyl group, more preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

The sulfonate anion in the sulfonate represented by the formula (B1) is preferably an anion represented by the formula (b1-1-1) to the formula (b1-1-9). In the following formulas, the definitions of the symbols have the same meaning as described above, and R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group).
Specific examples of the sulfonate anion in the salt represented by the formula (B1) include the anions described in JP 2010-204646 A.

Examples of the cation Z1 ⁺ contained in the acid generator (B1) include organic onium cations such as organic sulfonium cation, organic iodonium cation, organic ammonium cation, benzothiazolium cation, and organic phosphonium cation. A sulfonium cation or an organic iodonium cation is preferable, and an arylsulfonium cation is more preferable.
Z1 ⁺ in the formula (B1) is preferably the same as the cation represented by any one of the formulas (Z1) to (Z5) described above.

  As an acid generator (B), what is represented by a formula (B1-1)-a formula (B1-20) is mentioned, for example. Among them, an acid generator containing an arylsulfonium cation is preferable. Formula (B1-1), Formula (B1-2), Formula (B1-3), Formula (B1-6), Formula (B1-7), Formula (B1) -11), formula (B1-12), formula (B1-13), formula (B1-14), formula (B1-18), formula (B1-19) or formula (B1-20). More preferred are salts.

In the resist composition of the present invention, when only the acid generator (II) is contained as the acid generator, the content of the acid generator (II) is preferably 1 with respect to 100 parts by mass of the resin (A). It is at least part by mass (more preferably at least 3 parts by mass), preferably at most 30 parts by mass (more preferably at most 25 parts by mass).
When the resist composition contains the acid generator (II) and the acid generator (B), the total amount of the acid generator (II) and the acid generator (B) is 100 masses of the resin (A). The amount is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 40 parts by mass or less (more preferably 35 parts by mass or less). In this case, the content ratio (mass) of the acid generator (II) and the acid generator (B) is, for example, 5:95 to 95: 5, preferably 10:90 to 90:10, more preferably 15: 85-85: 15.

<Solvent (E)>
The content rate of the solvent (E) contained in the resist composition of this invention is 90 mass% or more in a resist composition, for example, Preferably it is 92 mass% or more, More preferably, it is 94 mass% or more, for example, 99.9. It is not more than mass%, preferably not more than 99 mass%. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and And esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (E) may contain 1 type independently, and may contain 2 or more types.

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The basic compound (C) is a compound that acts as a quencher.
The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by the formula (C1) to a compound represented by the formula (C8), more preferably a compound represented by the formula (C1-1). It is done.

［式（Ｃ１）中、Ｒ^c1、Ｒ^c2及びＲ^c3は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基、炭素数５〜１０の脂環式炭化水素基又は炭素数６〜１０の芳香族炭化水素基を表し、該アルキル基及び該脂環式炭化水素基に含まれる水素原子は、ヒドロキシ基、アミノ基又は炭素数１〜６のアルコキシ基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。］

[In formula (C1), R ^c1 , R ^c2 and R ^c3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or 6 to 6 carbon atoms. 10 represents an aromatic hydrocarbon group, and the hydrogen atom contained in the alkyl group and the alicyclic hydrocarbon group may be substituted with a hydroxy group, an amino group or an alkoxy group having 1 to 6 carbon atoms, The hydrogen atom contained in the aromatic hydrocarbon group is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms. It may be substituted with a group hydrocarbon group. ]

［式（Ｃ１−１）中、Ｒ^c2及びＲ^c3は、上記と同じ意味を表す。
Ｒ^c4は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基を表す。
ｍ３は０〜３の整数を表し、ｍ３が２以上のとき、複数のＲ^c4は同一又は相異なる。］

[In Formula (C1-1), R ^c2 and R ^c3 represent the same meaning as described above.
R ^c4 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
m3 represents an integer of 0 to 3, and when m3 is 2 or more, the plurality of R ^c4 are the same or different. ]

［式（Ｃ２）、式（Ｃ３）及び式（Ｃ４）中、Ｒ^c5、Ｒ^c6、Ｒ^c7及びＲ^c8は、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c9は、炭素数１〜６のアルキル基、炭素数３〜６の脂環式炭化水素基又は炭素数２〜６のアルカノイル基を表す。
ｎ３は０〜８の整数を表し、ｎ３が２以上のとき、複数のＲ^c9は同一又は相異なる。］

[In Formula (C2), Formula (C3) and Formula (C4), R ^c5 , R ^c6 , R ^c7 and R ^c8 each independently represent the same meaning as R ^c1 .
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an alkanoyl group having 2 to 6 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 are the same or different. ]

［式（Ｃ５）及び式（Ｃ６）中、Ｒ^c10、Ｒ^c11、Ｒ^c12、Ｒ^c13及びＲ^c16は、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c14、Ｒ^c15及びＲ^c17は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
ｏ３及びｐ３は、それぞれ独立に、０〜３の整数を表し、ｏ３が２以上であるとき、複数のＲ^c14は同一又は相異なり、ｐ３が２以上であるとき、複数のＲ^c15は、同一又は相異なる。
Ｌ^c1は、炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

[In Formula (C5) and Formula (C6), R ^c10 , R ^c11 , R ^c12 , R ^c13 and R ^c16 each independently represent the same meaning as R ^c1 .
R ^c14 , R ^c15 and R ^c17 each independently represent the same meaning as R ^c4 .
o3 and p3 each independently represent an integer of 0 to 3. When o3 is 2 or more, the plurality of R ^c14 are the same or different, and when p3 is 2 or more, the plurality of R ^c15 are the same. Or different.
L ^c1 represents an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

［式（Ｃ７）及び式（Ｃ８）中、Ｒ^c18、Ｒ^c19及びＲ^c20は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
ｑ３、ｒ３及びｓ３は、それぞれ独立に、０〜３の整数を表し、ｑ３が２以上であるとき、複数のＲ^c18は同一又は相異なり、ｒ３が２以上であるとき、複数のＲ^c19は同一又は相異なり、及びｓ３が２以上であるとき、複数のＲ^c20は同一又は相異なる。
Ｌ^c2は、単結合又は炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

Wherein (C7) and formula ^{(C8), R c18, R} c19 and R ^c20 in each occurrence independently represent the same meaning as R ^c4.
q3, r3 and s3 each independently represents an integer of 0 to 3, and when q3 is 2 or more, the plurality of R ^c18 are the same or different, and when r3 is 2 or more, the plurality of R ^c19 are When the same or different and s3 is 2 or more, the plurality of R ^c20 are the same or different.
L ^c2 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

In the formulas (C1) to (C8), examples of the alkyl group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, the alkoxy group, and the alkanediyl group are the same as those described above.
Examples of the alkanoyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, and 2,2-dimethylpropionyl group.

  Examples of the compound represented by the formula (C1) include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N- Dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tri Pentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonyl Amine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2- Examples include diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and preferably diisopropyl. Piruanirin. Particularly preferred include 2,6-diisopropylaniline.

Examples of the compound represented by the formula (C2) include piperazine.
Examples of the compound represented by the formula (C3) include morpholine.
Examples of the compound represented by the formula (C4) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound represented by the formula (C5) include 2,2′-methylenebisaniline.
Examples of the compound represented by the formula (C6) include imidazole and 4-methylimidazole.
Examples of the compound represented by the formula (C7) include pyridine and 4-methylpyridine.
Examples of the compound represented by the formula (C8) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1, 2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipiconylamine, bipyridine and the like.

  As ammonium salts, tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethyl Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like can be mentioned.

  The content of the basic compound (C) is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass, and particularly preferably based on the solid content of the resist composition. It is about 0.01-1 mass%.

<Other components (hereinafter sometimes referred to as “other components (F)”)>
The resist composition of this invention may contain the other component (F) as needed. The other component (F) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, and the like can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A) containing a resin (A1) and a resin (A2), an acid generator, and a solvent (E), basic compound (C) and other components used as necessary. It can be prepared by mixing (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature range from the range of 10-40 degreeC according to the kind etc. of resin, the solubility with respect to solvent (E), such as resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) A step of applying the resist composition of the present invention on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure and (5) a step of developing the composition layer after heating.

  Application of the resist composition onto the substrate can be performed by a commonly used apparatus such as a spin coater.

By drying the composition after coating, the solvent is removed and a composition layer is formed. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking) or using a decompression device to form a composition layer from which the solvent has been removed. The temperature in this case is preferably about 50 to 200 ° C., for example. The pressure is preferably about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. Exposure light sources include those that emit laser light in the ultraviolet region, such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser) Etc.) Using various lasers such as those that convert wavelength of laser light from the laser and emit harmonic laser light in the far-ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams or extreme ultraviolet light (EUV), etc. Can do.

The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection group reaction. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.
The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., for example, and the development time is preferably 5 to 300 seconds, for example.
The composition layer after heating is usually developed using a developer containing butyl acetate or 2-heptanone using a developing device.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline). The alkali developer may contain a surfactant.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove the water remaining on the substrate and the pattern.

In the case of producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
Organic solvents contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether Examples include ether solvents; amide solvents such as N, N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
In the organic developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and still more preferably only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. In the organic developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and substantially butyl acetate and / or 2 -More preferred is heptanone alone.
The organic developer may contain a surfactant. The organic developer may contain a trace amount of water.
At the time of development, the development may be stopped by substituting a solvent of a different type from the organic developer.

It is preferable to wash the developed resist pattern with a rinse solution. The rinsing liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, and an alcohol solvent or an ester solvent is preferable.
After the cleaning, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

<Application>
The resist composition of the present invention is a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, particularly a liquid. It is suitable as a resist composition for immersion exposure and useful for fine processing of semiconductors.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The structure of the compound was confirmed by MASS (LC: Agilent 1100 type, MASS: Agilent LC / MSD type or LC / MSD TOF type).
The composition ratio of the resin (A) (copolymerization ratio of the structural unit derived from each monomer used for the production of the resin (A) to the resin (A)) is the amount of unreacted monomer in the reaction liquid after the polymerization is finished. It measured using the chromatography, and computed by calculating | requiring the monomer amount used for superposition | polymerization from the obtained result. The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore HXL-M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

式（Ｈ−１）で表される化合物２５部、テトラヒドロフラン１７５部及びピリジン１１．８６部を仕込み、２３℃で３０分間攪拌した後、５℃に冷却し、式（Ｈ−２）で表される化合物１４．８２部を３０分かけて添加した。５℃で１時間攪拌した後、酢酸エチル３４０部、５％塩酸６６部及びイオン交換水８５部を添加し、攪拌後、分液を行った。回収された有機層に、１０％炭酸カリウム水溶液５５部を添加し、攪拌後、分液を行った。回収された有機層に、イオン交換水８５部を添加し、攪拌後、分液を行った。この水洗の操作を５回行った。回収された有機層を濃縮することにより、式（Ｈ−３）で表される化合物２８．６２部を得た。

式（Ｈ−４）で表される化合物１０．６９部、ジメチルホルムアミド５３．４７部、炭酸カリウム８．５８部及びヨウ化カリウム１．０３部を仕込み、４０℃で１時間攪拌した後、式（Ｈ−３）で表される化合物２８．６２部及びジメチルホルムアミド５７．２４部の混合溶液を３０分かけて添加した。４０℃で６時間攪拌した後、２３℃まで冷却した。得られた反応マスに、クロロホルム６７０部及び５％シュウ酸水溶液１６６部を添加し、攪拌後、分液を行った。回収された有機層に、イオン交換水２６５部を添加し、攪拌後、分液を行った。この水洗の操作を６回行った。回収された有機層を濃縮した後、得られた濃縮マスに、アセトニトリル７．５８部及び酢酸エチル２６．５３部を添加、３時間攪拌した後、ろ過することにより、式（Ｈ）で表される化合物３２．１３部を得た。 Synthesis Example 1: Synthesis of compound represented by formula (H)

25 parts of the compound represented by the formula (H-1), 175 parts of tetrahydrofuran and 11.86 parts of pyridine were charged, stirred at 23 ° C. for 30 minutes, cooled to 5 ° C., and represented by the formula (H-2). 14.82 parts of the above compound was added over 30 minutes. After stirring at 5 ° C. for 1 hour, 340 parts of ethyl acetate, 66 parts of 5% hydrochloric acid and 85 parts of ion-exchanged water were added, followed by liquid separation after stirring. To the collected organic layer, 55 parts of a 10% potassium carbonate aqueous solution was added, and after separation, liquid separation was performed. To the recovered organic layer, 85 parts of ion-exchanged water was added, followed by liquid separation after stirring. This washing operation was performed 5 times. By concentrating the collected organic layer, 28.62 parts of a compound represented by the formula (H-3) was obtained.

10.69 parts of the compound represented by the formula (H-4), 53.47 parts of dimethylformamide, 8.58 parts of potassium carbonate and 1.03 parts of potassium iodide were charged and stirred at 40 ° C. for 1 hour. A mixed solution of 28.62 parts of the compound represented by (H-3) and 57.24 parts of dimethylformamide was added over 30 minutes. After stirring at 40 ° C. for 6 hours, the mixture was cooled to 23 ° C. To the obtained reaction mass, 670 parts of chloroform and 166 parts of a 5% aqueous oxalic acid solution were added, followed by liquid separation after stirring. To the collected organic layer, 265 parts of ion-exchanged water was added, followed by liquid separation after stirring. This washing operation was performed 6 times. After the collected organic layer was concentrated, 7.58 parts of acetonitrile and 26.53 parts of ethyl acetate were added to the resulting concentrated mass, and the mixture was stirred for 3 hours, and then filtered, and expressed by the formula (H). 32.13 parts of compound were obtained.

Synthesis Example 2: Synthesis of salt represented by formula (II-1)

A salt represented by the formula (II-1-a) was synthesized by the method described in JP-A-2007-224008.
10.00 parts of the salt represented by the formula (II-1-a) and 40 parts of 1,2-dichloroethane were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 5.53 parts of the compound represented by the formula (II-1-b) and 0.30 parts of p-toluenesulfonic acid were added, and the mixture was refluxed and stirred at 100 ° C. for 3 hours. The obtained reaction product was cooled to 23 ° C., 120.00 parts of chloroform and 35.39 parts of an 8.7% aqueous sodium hydrogen carbonate solution were added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated. To the recovered organic layer, 120 parts of ion-exchanged water was charged, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed 7 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 20 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To this, 8.14 parts of acetonitrile and 48.84 parts of tert-butyl methyl ether were added and stirred, stirred at 23 ° C. for 1 hour, filtered, and 8.25 of the salt represented by the formula (II-1). Got a part.

MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 467.1

式（ＩＩ−２−ｂ）で表される塩を、特開２００８−９４８３５号公報に記載された方法で合成した。
式（ＩＩ−２−ａ）で表される塩１７．５０部、式（ＩＩ−２−ｂ）で表される塩２５．００部(純度：９０．８％)、クロロホルム１２５．００部及びイオン交換水４１．６７部を仕込み、２３℃で１２時間攪拌し、分液を行った。回収された有機層に、イオン交換水３１．２５部を仕込み、攪拌、分液を行った。この水洗を９回行った。得られた有機層に活性炭１．００部を仕込み、２３℃で３０分間攪拌し、ろ過した。ろ液を濃縮した後、得られた濃縮物に、アセトニトリル５０部を添加して溶解し、濃縮し、得られた残渣にｔｅｒｔ−ブチルメチルエーテル１７３．１３部を加えて攪拌し、ろ過することにより、式（ＩＩ−２−ｃ）で表される塩２８．４２部を得た。 Synthesis Example 3: Synthesis of salt represented by formula (II-2)

A salt represented by the formula (II-2-b) was synthesized by the method described in JP 2008-94835 A.
17.50 parts of the salt represented by the formula (II-2-a), 25.00 parts of the salt represented by the formula (II-2-b) (purity: 90.8%), 125.00 parts of chloroform, 41.67 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 12 hours for liquid separation. The recovered organic layer was charged with 31.25 parts of ion exchanged water, and stirred and separated. This washing with water was performed nine times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. Concentrate the filtrate, add 50 parts of acetonitrile to the resulting concentrate, dissolve, concentrate, add 173.13 parts of tert-butyl methyl ether to the resulting residue, stir and filter. Gave 28.42 parts of the salt represented by the formula (II-2-c).

式（ＩＩ−２−ｃ）で表される塩１０．７２部及び１，２−ジクロロエタン４２．８８部を仕込み、２３℃で３０分間攪拌した。その後、式（ＩＩ−１−ｂ）で表される化合物５．５３部及びｐ−トルエンスルホン酸０．３０部を添加し、１００℃で、３時間還流攪拌した。得られた反応物を２３℃まで冷却し、クロロホルム１２０．００部及び８．７％炭酸水素ナトリウム水溶液３５．３９部を加え、２３℃で３０分間攪拌した。その後、静置し、分液した。回収された有機層に、イオン交換水１２０部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を７回行った。得られた有機層に活性炭１．００部を仕込み、２３℃で３０分間攪拌し、ろ過した。ろ液を濃縮し、得られた濃縮物に、アセトニトリル２０部を添加して溶解し、濃縮した。これに、アセトニトリル９．１２部及びｔｅｒｔ−ブチルメチルエーテル５４．７２部を加えて攪拌し、２３℃で１時間攪拌し、ろ過して、式（ＩＩ−２）で表される塩８．４９部を得た。

10.72 parts of a salt represented by the formula (II-2-c) and 42.88 parts of 1,2-dichloroethane were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 5.53 parts of the compound represented by the formula (II-1-b) and 0.30 parts of p-toluenesulfonic acid were added, and the mixture was refluxed and stirred at 100 ° C. for 3 hours. The obtained reaction product was cooled to 23 ° C., 120.00 parts of chloroform and 35.39 parts of an 8.7% aqueous sodium hydrogen carbonate solution were added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated. To the recovered organic layer, 120 parts of ion-exchanged water was charged, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed 7 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 20 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To this, 9.12 parts of acetonitrile and 54.72 parts of tert-butyl methyl ether were added and stirred, stirred at 23 ° C. for 1 hour, filtered, and 8.49 of the salt represented by the formula (II-2). Got a part.

MS (ESI (+) Spectrum): M ⁺ 305.1
MS (ESI (-) Spectrum): M ^- 467.1

Synthesis Example 4: Synthesis of salt represented by formula (II-3)

  10.00 parts of the compound represented by the formula (II-3-b) obtained by the method described in JP2008-209917A, and the salt 11.26 represented by the formula (II-3-a) Part, chloroform 50 parts and ion-exchanged water 25 parts, and stirred at 23 ° C. for 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the resulting residue, the mixture was stirred at 23 ° C. for 30 minutes, and then filtered to obtain the salt 11 represented by the formula (II-3-c). .75 parts were obtained.

式（ＩＩ−３−ｃ）で表される塩１１．７１部、式（ＩＩ−３−ｄ）で表される化合物１．７０部及びモノクロロベンゼン４６．８４部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．１２部を添加した後、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮した後、得られた残渣に、クロロホルム５０部及びイオン交換水１２．５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１２．５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を８回繰り返した。得られた有機層を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて攪拌した後、ろ過することにより、式（ＩＩ−３−ｅ）で表される塩６．８４部を得た。

11.71 parts of a salt represented by the formula (II-3-c), 1.70 parts of a compound represented by the formula (II-3-d) and 46.84 parts of monochlorobenzene were charged and the mixture was charged at 23 ° C. for 30 minutes. Stir. After adding 0.12 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added to the obtained residue and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 12.50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 8 times. After concentration of the obtained organic layer, 50 parts of tert-butyl methyl ether was added to the resulting residue, stirred, and then filtered to obtain the salt represented by the formula (II-3-e) 6. 84 parts were obtained.

式（ＩＩ−３−ｅ）で表される塩４．９８部及びクロロホルム２５．００部を仕込み、２３℃で３０分間攪拌した。その後、式（ＩＩ−１−ｂ）で表される化合物２．１７部及び硫酸０．０９部を添加し、６０℃で、１５時間還流攪拌した。得られた反応物を２３℃まで冷却し、イオン交換水１２０部を加え、２３℃で３０分間攪拌した。その後、静置し、分液した。回収された有機層に、イオン交換水１２．５０部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を７回行った。得られた有機層に活性炭１．００部を仕込み、２３℃で３０分間攪拌し、ろ過した。ろ液を濃縮し、得られた濃縮物に、アセトニトリル１０部を添加して溶解し、濃縮した。これに、ｔｅｒｔ−ブチルメチルエーテル４１．３５部を加えて攪拌した後、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（ＩＩ−３）で表される塩４．８４部を得た。

4.98 parts of the salt represented by the formula (II-3-e) and 25.00 parts of chloroform were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 2.17 parts of a compound represented by the formula (II-1-b) and 0.09 part of sulfuric acid were added, followed by stirring at 60 ° C. for 15 hours. The obtained reaction product was cooled to 23 ° C., 120 parts of ion exchange water was added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated. The recovered organic layer was charged with 12.50 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed 7 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 10 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To this, 41.35 parts of tert-butyl methyl ether was added and stirred, and then the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 4.84 parts of the salt represented by the formula (II-3).

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (−) Spectrum): M ^- 467.1

式（Ｂ１−５−ａ）で表される塩５０．４９部及びクロロホルム２５２．４４部を反応器に仕込み、２３℃で３０分間攪拌した後、式（Ｂ１−５−ｂ）で表される化合物１６．２７部を滴下し、２３℃で１時間攪拌することにより、式（Ｂ１−５−ｃ）で表される塩を含む溶液を得た。得られた式（Ｂ１−５−ｃ）で表される塩を含む溶液に、式（Ｂ１−５−ｄ）で表される塩４８．８０部及びイオン交換水８４．１５部を添加し、２３℃で１２時間攪拌した。得られた反応液が２層に分離していたので、クロロホルム層を分液して取り出し、更に、該クロロホルム層にイオン交換水８４．１５部を添加し、水洗した。この操作を５回繰り返した。得られたクロロホルム層に、活性炭３．８８部を添加攪拌し、ろ過した。回収されたろ液を濃縮し、得られた残渣に、アセトニトリル１２５．８７部を添加攪拌し、濃縮した。得られた残渣に、アセトニトリル２０．６２部及びｔｅｒｔ−ブチルメチルエーテル３０９．３０部を加えて２３℃で３０分間攪拌し、上澄み液を除去し、濃縮した。得られた残渣に、ｎ−ヘプタン２００部を添加、２３℃で３０分間攪拌し、ろ過することにより、式（Ｂ１−５）で表される塩６１．５４部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３７５．２
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３３９．１ Synthesis Example 5: Synthesis of salt represented by formula (B1-5)

50.49 parts of the salt represented by the formula (B1-5-a) and 252.44 parts of chloroform are charged into a reactor, stirred at 23 ° C. for 30 minutes, and then represented by the formula (B1-5-b). 16.27 parts of the compound was added dropwise and stirred at 23 ° C. for 1 hour to obtain a solution containing a salt represented by the formula (B1-5-c). To the obtained solution containing the salt represented by the formula (B1-5-c), 48.80 parts of the salt represented by the formula (B1-5-d) and 84.15 parts of ion-exchanged water are added, The mixture was stirred at 23 ° C. for 12 hours. Since the resulting reaction solution was separated into two layers, the chloroform layer was separated and removed, and 84.15 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. To the obtained chloroform layer, 3.88 parts of activated carbon was added and stirred, followed by filtration. The collected filtrate was concentrated, and 125.87 parts of acetonitrile was added to the resulting residue, and the mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated. To the obtained residue, 200 parts of n-heptane was added, stirred at 23 ° C. for 30 minutes, and filtered to obtain 61.54 parts of the salt represented by the formula (B1-5).
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (−) Spectrum): M ^- 339.1

Resin Synthesis The compounds (monomers) used in the resin synthesis are shown below.

[Synthesis of Resin A1-1]
Monomer (H) and monomer (I) are used as monomers and mixed so that the molar ratio (monomer (H): monomer (I)) is 90:10. Dioxane was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 72 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A1-1 (copolymer) having a weight average molecular weight of 1.4 × 10 ^{4 in} a yield of 75%. Got in. This resin A1-1 has the following structural units.

[Synthesis of Resin A1-2]
Monomer (H) was used as a monomer, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A1-2 having a weight average molecular weight of 1.8 × 10 ^{4 in} a yield of 75%. This resin A1-2 has the following structural units.

[Synthesis of Resin A2-1]
Monomer (D), monomer (E), monomer (B), monomer (F), and monomer (C) are in a molar ratio [monomer (D): monomer (E): monomer (B): monomer (F): Monomer (C)] was mixed at 30: 14: 6: 20: 30, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.0. × give 10 ³ of copolymer in 60% yield. This copolymer has the following structural units and is designated as resin A2-1.

[Synthesis of Resin A2-2]
Monomer (A), monomer (E), monomer (B), monomer (F) and monomer (C) are mixed so that the molar ratio is 30: 14: 6: 20: 30, and the total amount of monomers Of 1.5 mass times of dioxane was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.2. × give 10 ³ of copolymer in 78% yield. This copolymer has the following structural units and is referred to as Resin A2-2.

[Synthesis of Resin A2-3]
Monomer (A), monomer (B) and monomer (C) are mixed so that the molar ratio [monomer (A): monomer (B): monomer (C)] is 50:25:25, , 1.5 mass times dioxane was mixed with respect to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. Then, this was heated at 80 ° C. for about 8 hours to carry out polymerization. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin is filtered and collected, dissolved again in dioxane, poured into a large amount of methanol / water mixed solvent to precipitate the resin, and the precipitated resin is filtered and collected three times for reprecipitation. Purification gave a copolymer having a weight average molecular weight of about 9.2 × 10 ³ in a yield of 60%. This copolymer has the following structural units and is designated as resin A2-3.

[Synthesis of Resin A2-4]
Monomer (D), monomer (L), monomer (B), monomer (C) and monomer (F) are mixed so that the molar ratio is 30: 14: 6: 20: 30, and the total amount of monomers Of 1.5 mass times of dioxane was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin obtained was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 8.2. × give 10 ³ of the copolymer at 68% yield. This copolymer has the following structural units and is designated as resin A2-4.

[Synthesis of Resin A2-5]
Monomer (D), monomer (L), monomer (K), monomer (C) and monomer (F) are mixed so that the molar ratio is 35: 15: 3: 27: 20, and the total amount of monomers Of 1.5 mass times of dioxane was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.9. × give 10 ³ of copolymer in 73% yield. This copolymer has the following structural units and is designated as resin A2-5.

[Synthesis of Resin A2-6]
Monomer (D), monomer (M), monomer (B), monomer (F) and monomer (C) are mixed in a molar ratio [monomer (D): monomer (M): monomer (B): monomer (F): Monomer (C)] was mixed at 30: 14: 6: 20: 30, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.4. × give 10 ³ of copolymer in 62% yield. This copolymer has the following structural units and is designated as resin A2-6.

[Synthesis of Resin A2-7]
Monomer (D), monomer (L), monomer (K), monomer (F), and monomer (C) are in a molar ratio [monomer (D): monomer (L): monomer (K): monomer (F): Monomer (C)] was mixed so as to be 45: 14: 2.5: 22: 16.5, and propylene glycol monomethyl ether acetate of 1.5 mass times the total monomer amount was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / ion-exchanged water = 4/1 mixing solution to precipitate a resin, which was filtered to obtain a copolymer having a weight average molecular weight of 7.8 × 10 ^3. The yield was 73%. This copolymer has the following structural units and is designated as resin A2-7.

[Synthesis of Resin X1]
Monomer (G), monomer (C), and monomer (B) are used as the monomers and mixed so that the molar ratio (monomer (G): monomer (C): monomer (B)) is 35:45:20. Then, 1.5 mass times dioxane of the total monomer amount was added to make a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.0 mol% and 3.0 mol%, respectively, based on the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.0. A × 10 ³ resin X1 (copolymer) was obtained in a yield of 75%. This resin X1 has the following structural units. The molar ratio of each structural unit is structural unit (G): structural unit (C): structural unit (B) = 34.7: 45.4: 19.9.

[Synthesis of Resin X2]
As the monomer, the monomer (J) and the monomer (G) are used and mixed so that the molar ratio (monomer (J): monomer (G)) is 80:20. Dioxane was added to make a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.5 mol% and 1.5 mol%, respectively, based on the total monomer amount, and these were added at 70 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 2.8. A × 10 ⁴ resin X2 (copolymer) was obtained in a yield of 70%. This resin X2 has the following structural units. The molar ratio of each structural unit was structural unit (J): structural unit (G) = 80.2: 19.8.

<Preparation of resist composition>
A mixture obtained by mixing and dissolving the components shown in Table 1 was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

ＩＩ−２：

ＩＩ−３：

Ｂ１−３：特開２０１０−１５２３４１号公報の実施例に従って合成

Ｂ１−５：

Ｂ２：ＷＯ２００８／９９８６９号の実施例及び特開２０１０−２６４７８の実施例に従って合成

Ｂ３：特開２００５−２２１７２１の実施例に従って合成

<Resin>
A1-1, A1-2, A2-1 to A2-5, X1, X2 synthesized by resin synthesis
<Acid generator>
II-1:

II-2:

II-3:

B1-3: synthesized according to the example of JP 2010-152341 A

B1-5:

B2: synthesized according to examples of WO2008 / 99869 and JP2010-26478

B3: synthesized according to the example of JP-A-2005-221721

<Basic compound: Quencher>
C1: 2,6-diisopropylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Solvent>
Propylene glycol monomethyl ether acetate 265.0 parts Propylene glycol monomethyl ether 20.0 parts 2-heptanone 20.0 parts γ-butyrolactone 3.5 parts

<Manufacture of resist pattern>
An organic antireflective coating composition (ARC-29; manufactured by Nissan Chemical Co., Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to form an organic antireflective coating having a thickness of 78 nm. Formed. Next, the above resist composition was spin-coated on this organic antireflection film so that the film thickness after drying was 85 nm. The silicon wafer coated with the resist composition was pre-baked on a direct hot plate at the temperature described in the “PB” column of Table 1 for 60 seconds to form a resist composition layer. A contact hole pattern (hole pitch) is formed on a silicon wafer on which a resist composition layer has been formed using an ArF excimer stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light). Using a mask for forming (100 nm / hole diameter 70 nm), the exposure amount was changed stepwise to perform exposure. Note that ultrapure water was used as the immersion medium.
After the exposure, the silicon wafer was post-exposure baked on a hot plate at a temperature described in the “PEB” column of Table 1 for 60 seconds. Next, this silicon wafer was subjected to paddle development for 60 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution.

  From each resist composition layer, an exposure amount at which the hole diameter of a pattern formed with a mask having a hole diameter of 70 nm was 55 nm was defined as effective sensitivity.

<Focus margin evaluation (DOF)>
In the effective sensitivity, when the focus was changed, the range (52.5 to 57.7 nm) in which the line width was 55 nm ± 5% was used as the line width index, and the DOF was evaluated according to the following four levels. In other words, those having a DOF of 0.20 μm or more are indicated with “◎”,
“○” indicates that the thickness is 0.12 μm or more and less than 0.20 μm,
What was less than 0.12 micrometer was made into "x".
The results are shown in Table 2. In Table 2, the numbers in parentheses indicate DOF values (μm).

<Defect evaluation>
The resist composition was applied (spin coated) to a 12-inch silicon wafer (substrate) so that the film thickness after drying was 0.15 μm. After coating, the composition layer was formed on the wafer by pre-baking (PB) for 60 seconds on the direct hot plate at the temperature shown in the PB column of Table 1.
The wafer on which the composition layer was formed in this manner was subjected to water rinsing for 60 seconds using a developing machine [ACT-12; manufactured by Tokyo Electron Ltd.].
Thereafter, the number of defects on the wafer was measured using a defect inspection apparatus [KLA-2360; manufactured by KLA Tencor]. The results are shown in Table 2.

<Preparation of resist composition>
Each of the components shown below was dissolved in the following solvent in parts by mass shown in Table 3, and further filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare a resist composition.

<Manufacture of negative resist pattern>
<Immersion exposure evaluation of resist composition>
An organic antireflective coating composition (ARC-29; manufactured by Nissan Chemical Co., Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to form an organic reflective film having a thickness of 78 nm on the wafer. A prevention film was formed. Next, on the organic antireflection film, the above resist composition was applied (spin coated) so that the film thickness after drying was 85 nm. After coating, the silicon wafer was pre-baked on a direct hot plate for 60 seconds at the temperature described in the “PB” column of Table 3 to form a composition layer. ArF excimer stepper for immersion exposure (XT: 1900Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light) on a silicon wafer on which the composition layer is formed, and a contact hole pattern (hole pitch 90 nm) Using a mask for forming a hole diameter of 55 nm), the exposure amount was changed stepwise. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 3. Next, the composition layer on the silicon wafer is developed by using a butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution by a dynamic dispensing method at 23 ° C. for 20 seconds, thereby forming a negative resist pattern. Manufactured.

  In the resist pattern obtained after development, the exposure amount at which the hole diameter formed using the mask was 45 nm was defined as the effective sensitivity.

<Focus margin evaluation (DOF)>
In terms of effective sensitivity, when the focus was changed, the range (42.7 to 47.3 nm) in which the line width was 45 nm ± 5% was used as the line width index, and the DOF was evaluated at the following level. In other words, “○” indicates that the DOF is 0.10 μm or more,
What was less than 0.10 micrometer was made into "x".
The results are shown in Table 4. In Table 4, numbers in parentheses indicate DOF values (μm).
<Defect evaluation>
ArF excimer laser stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized illumination] for forming a 1: 1 line and space pattern (pitch 80 nm) Using the mask, a negative resist pattern was manufactured by performing the same operation as above except that exposure was performed with an exposure amount at which the line width and space width of the obtained line and space pattern were 1: 1.
Thereafter, the number of defects (pieces) on the line pattern on the wafer was measured using a defect inspection apparatus [KLA-2360; manufactured by KLA Tencor]. The results are shown in Table 4.

  According to the resist composition of the present invention, the focus margin (DOF) at the time of producing the resist pattern is good, and the number of defects can be reduced when the resist pattern is formed.

Claims (7)

(A1) a resin having a structural unit represented by formula (I),
(A2) A resist composition containing a resin having an acid labile group and (B) an acid generator represented by formula (II).

[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ _{is, - (CH 2) m1 -} , - (CH 2) m2 -O- (CH 2) m3 - or _{- (CH 2) m4 -CO-} O- (CH 2) m5 - represents a.
m1 to m5 each independently represents an integer of 1 to 6.
R ² represents a C 1-10 hydrocarbon group having a fluorine atom. ]

[In the formula (II),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon ring may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the alicyclic hydrocarbon ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. May be substituted.
R ^f1 and R ^f2 each independently represent a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
s represents an integer of 1 to 10, and when s is 2 or more, the plurality of R ^f1 and R ^f2 are the same or different.
Z ⁺ represents an organic cation. ] The resist composition according to claim 1, wherein R ² is a fluorinated alkyl group having 1 to 6 carbon atoms. The resist composition according to claim 1, wherein A ¹ is a methylene group. The ring W is a ring represented by the formula (IIa1-1), a ring represented by the formula (IIa1-2), or a ring represented by the formula (IIa1-3). Resist composition.

[In Formula (IIa1-1), Formula (IIa1-2) and Formula (IIa1-3),
The methylene group contained in the ring may be replaced by an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, or a carbon number. It may be substituted with an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. ] L ¹ is * —CO—O— (CH ₂ ) _t — (t represents an integer of 0 to 6. * represents a bond to —C (Q ¹ ) (Q ² ) —). The resist composition according to any one of claims 1 to 4.   Furthermore, the resist composition in any one of Claims 1-5 containing a solvent. (1) The process of apply | coating the resist composition in any one of Claims 1-6 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating,
A method for producing a resist pattern including: